TOP OF THE LADDER: Marine Operations in the Northern Solomons
by Captain John C. Chapin, USMCR (Ret)

Planning the Operation

LtGen Alexander A. Vandegrift was an early commander of
IMAC.Department of Defense Photo (USMC) 61899

This kind of strong enemy reaction, in the air and at
sea, had been expected by American staff officers who had put in long
weeks planning the Bougainville operation. Looking at a map of the
Solomon Islands chain, it was obvious that this largest island (130 by
30 miles) on the northwest end was a prime objective to cap the long and
painful progress northward from the springboard of Guadalcanal at the
south end. As Guadalcanal had been the beginning of the island chain, so
now Bougainville would mark the top of the ladder in the Northern
Solomons. From Bougainville air fields, American planes could neutralize
the crucial Japanese base of Rabaul less than 250 miles away on New
Britain. From Bougainville, the enemy could defend his massive air-naval
complex at Rabaul. "Viewed from either camp, the island was a priority
possession."

There were the usual sequences of high level planning
conferences, but, on 1 October 1943, Admiral William F. Halsey,
Commander, South Pacific Area, notified General Douglas MacArthur,
Supreme Allied Commander, Southwest Pacific Area, that the beaches on
Empress Augusta Bay in the middle of Bougainville's west coast would be
the main objective. This location was selected as the point to strike
because with the main Japanese forces 25 miles away at the opposite
north and south ends of the island, it would be the point of least
opposition. In addition, it provided a natural defensive region once the
Marines had landed and their airfields had been gouged out of the swamp
and jungle. Finally, the target area would provide a site for a
long-range radar installation and an advanced naval base for PT (patrol
torpedo) boats.

It promised to be a campaign in a miserable location.
And it was. There were centipedes three fingers wide, butterflies as big
as little birds, thick and nearly impenetrable jungles, bottomless man
grove swamps, crocodile infested rivers, millions of insects, and heavy
daily torrents of rain with enervating humidity.

Major General Allen H. Turnage, the 3d Marine
Division commander, summarized these horrors. "Never had men in the
Marine Corps had to fight and maintain themselves over such difficult
terrain as was encountered on Bougainville."

To carry out this operation, Lieutenant General
Alexander A. Vandegrift, Commanding General, I Marine Amphibious Corps
(IMAC),* had in his command for the operation:

* Gen Vandegrift, 1st Marine Division
commander on Guadalcanal, relieved MajGen Clayton B. Vogel as IMAC
commander in July 1943. He in turn was relieved as IMAC commander by
MajGen Charles D. Barrett on 27 September. Gen Vandegrift was on his way
home to Washington to become 18th Commandant of the Marine Corps when,
on the sudden death of Gen Barrett on 8 October, he was recalled to the
Pacific to resume command of IMAC and lead it in the Bougainville
operation. He, in turn, was relieved by MajGen Roy S. Geiger on 9
November.

The Marine riflemen in these units were supplemented
by a wide range of support: 155mm artillery; motor transport; amphibian
tractor; and signal, medical, special weapons, Seabee, and tank
battalions. The 3d Division had its own engineers and pioneers in the
19th Marines and artillery in the 12th Marines.

Immediately following Vandegrift's operation order,
practice landing exercises were conducted in the New Hebrides and on
Guadalcanal and Florida Islands.

The objectives assigned on Bougainville were to seize
a substantial beachhead and build airstrips. Then American planes could
assure final neutralization of the Japanese airfields at Kahili, Buka,
and Bonis airfields at the north and south ends of Bougainville. (By 31
October, American planes had initially rendered the Japanese fields
inoperable.) After that would come a massive increase in air operations
against Rabaul.

Facing the invading Marines was a formidable enemy
force dispersed on the island. At Buin, for instance, there were 21,800
Japanese. Responsible for the defense was an old adversary, Lieutenant
General Haruyoshi Hyakutake, commander of the Seventeenth Army,
and the man the Marines had defeated at Guadalcanal. His main force was
the 6th Division.

Working with the ground U. S. forces were the
aviators of Air Solomons: New Zealand fighters, Army Air Force bombers,
and the 1st and 2d Marine Aircraft Wings. As early as 15 August fighter
planes from VMF-214 (the famous Black Sheep squadron) had strafed the
Kahili airfield at the southern end of Bougainville. Now, in October,
there were repeated strikes against the Japanese planes at other
Bougainville airfields.

At sea, Halsey had designated Rear Admiral Theodore
S. Wilkinson as commander of Task Force 31. Under him were Rear Admiral
Frederick C. Sherman with the carriers (TF 38) and Rear Admiral Aaron S.
"Tip" Merrill with the cruisers and destroyers (TF 39). Their job was to
soften up the defenders before the landing and to safeguard the
Marine-held beachhead.